I have read so many great articles off this site and everyone seems extremely helpful. So I have been using a purposefully built smoker for a few years and now that my customer base has grown its time to build a bigger smoker and like so many others I just have a few questions.

All this is according to the calculators:

The tank is 36 x 62 cylinder
Fb 36 x 24H x 25W
Chimney 8" x 22"
it calls for only 2 inlets 12" x 4" but I want to put a 3rd directly across the throat opening based on what many ppl have said in here
Throat opening of 172.8 sq in. like 22in x 4" opening (which seems a tad small)

So my question is on the throat opening, seems like it should be taller than 4" in my own opinion but I am no expert. But i also need the same 22" x 4" opening on the opposite end to allow the smoke and heat into the CC correct? My plan is a baffle plate at that level which will dbl as my water pan maybe 1-2" deep should be sufficient with a drain valve.

Does all of this seem correct? Sorry no pics yet as I need to figure out just how much steel and other materials I will need to start. Thanks for all the input guys and y'all have some amazing builds!

Not really a concern with height of the throat as it is sq in that matters. With that said, a shape that is wider instead of taller is better since this will give you more room in the cook chamber (the baffle plate is at the same height as top of firebox so if throat is 8 inches high, you loose 8 inches of your cook chamber).

Trust the numbers....they will work.

An extra vent is always a good idea but mount as low as possible. A high mounted vent is called an exaust.

Your choice on a water pan. I sealed my baffle plate so I could use it as such but find it makes no difference so don’t bother anymore. Ball valves are expensive, I will not put one on my next pit as I don’t find it useful. Your choice, however.

Thanks DIRTY! I found later that Feldon's calulator was wrong and the throat opening was way to small. Found another and it came up with the same numbers as Pete has.

If y'all don't put a drain on you BP how do you get the grease and sludge out when you wash it down? Or do you just scrape it really good and scoop the chunks and junk out? Since I had planned on using it as a water pan I shouldn't need the lower dam to keep grease out of the FB. However on the opening opposing the throat inside the CC do I need to weld in a plate to divert the drippings onto the BP so the grease above doesn't drip down or do I basically just not use the last 8" of cooking area? Does that question make sense?

I do mainly butts and brisket and those meats produce a ton of drippings so I need to be able to drain it, I assume. Anyway I am also drawing this on my CAD software so I can get accurate measurements on how much steel to order and if I can afford a laser cutter I can send them the prints to cut everything for me. Once I have it all drawn up I will submit pics to show you my plan.

Oh last question is on that intake not a vent sorry! I read on someone's build they were told to put an intake directly across the throat to "push" air into the throat. If that isn't needed then I will just put all 3 intakes low just above my ash pan.

I do have a drain on the BP but I've only used it a few times over the years, I'd rather have it and not need it than need it and not have it. I just scrape the BP after I'm done cooking and the cooker has cooled. I wouldn't recommend putting anything above the BP gap because it'll get burnt before anything else gets done and it would restrict the airflow. The intakes should be as low as possible so that all the air has to pass through you fire/coals. It doesn't matter if they're on the sides of the FB or the door.

Pete does have a point on the drain in that It’s tough to add later. A thought is to pipe it in and just fit it with a threaded pipe-cap. If you decide you need it after a few cooks you could invest in the $50 ball valve and just screw it on. I put a separate drain on the bottom of my cook chamber (just in case I hosed it out sometime or had a big leak off the baffle plate). To this day, it is still capped off as unused.

I have loaded mine up with every kind of meat possible and every combination imaginable. My experience is that most of the drippings vaporize when they hit the baffle plate (thus adding moisture) and that I’m left with mainly charred sludge which easily scrapes off with a wide putty knife after it cools. I don’t ever hose mine out to clean it but mist it with water while still hot to “steam clean” it. If you are going to use a power washer on it like some do, a drain is a bigger necessity.

There really is no wrong answer, we just want to point out different view points.

AHHHHH!!!!! That all makes total sense now thank you! See right now all my drippings collect in a pan and gather so they don't really evaporate. I am new to the reverse flow as I am basically using direct heat at the bottom of my box then a pan and about 24" up to 36" I have my meat. Like an ugly drum smoker just not an ugly drum its a 4 drawer filing cabinet. It has worked amazingly well for over a year but it's totally inefficient and again my customer base has grown so I have out grown it.

I like the drain on the CC idea as well just incase. No no pressure washer just a hose as I thought that's how everyone cleaned there tanks out, I was wrong.